The Weird Mushroom has a 1 in 100 chance of spawning wherever a Super Mushroom is placed, except during upload check, where it was changed to never randomly spawn after an update. However, it can also be unlocked by clearing all four of the Nintendo World Championships courses. Upon unlocking the Weird Mushroom, the player can use it by shaking a Super Mushroom in the editor. In Super Mario Maker for Nintendo 3DS, however, the player starts the game with the Weird Mushroom in their item selection.

The Weird Mushroom is exclusive to the Super Mario Bros. game style, so if the player changes the game style, every Weird Mushroom object turns back into a Super Mushroom.